Serum amyloid A4 is a procoagulant apolipoprotein that it is elevated in venous thrombosis patients

Abstract Background Serum amyloid A4 (SAA4) is an apolipoprotein that is in the SAA family and it is constitutively translated. Previously, acute‐phase SAA1 and SAA2 levels were associated with venous thromboembolism (VTE). Objective We investigated the association of plasma SAA4 with VTE and the role of SAA4 in coagulation. Patients and Methods The association of SAA4 with VTE in a case‐control study of adult VTE subjects (N = 113 each group) and the effects of recombinant SAA4 on plasma blood coagulation assays and prothrombin activation initiated by factor Xa were evaluated. Results Plasma SAA4 levels in VTE subjects were higher vs. controls (48.1 vs. 38.4 µg/mL; P